摘要:
This invention is to generate encoded data within a target amount. A first encoding unit generates lossy encoded data of each pixel block by using a quantization matrix Qi specified by a parameter i. A second encoding unit generates lossless encoded data of each pixel block. Let Lx be the lossless encoded data length, and Ly be the lossy encoded data length. A control unit determines, using a nonlinear boundary function fi,j( ) specified by the parameters i and j, whether condition: Ly
摘要:
According to this invention, encoded data of a target data amount can be generated by one image input operation while both lossless encoding and lossy encoding are adopted. For this purpose, a first encoding unit which generates lossy encoded data, a second encoding unit which generates lossless encoded data, and an attribute determination unit which detects the number of colors in a pixel block to be encoded parallel-process the same pixel block. When the number of colors in the pixel block of interest is equal to or smaller than a predetermined number, an encoding sequence control unit stores lossless encoded data in a first memory. When the number of colors exceeds the predetermined number, the encoding sequence control unit stores encoded data of a shorter code length among lossy encoded data and lossless encoded data in the first memory.
摘要:
According to this invention, encoded data of a target data amount is generated by one image input operation while both lossless encoding and lossy encoding are adopted. For this purpose, a first memory stores encoded data of a shorter encode length among encoded data generated by a first encoding unit which performs lossy encoding and encoded data generated by a second encoding unit which performs lossless encoding. A second memory stores encoded data from a second encoding unit. When an encoding sequence control unit determines that the encoded data amount in the first memory has exceeded the target data amount, the encoding sequence control unit discards data in the first memory, sets a quantization parameter for a higher compression ratio for the first encoding unit, and causes the first encoding unit to execute encoding. Encoded data before the encoded data amount is determined to have exceeded the target data amount is re-encoded by a re-encoding unit.
摘要:
This invention generates efficient encoded data to restore original image data from reduced image data. An input unit inputs block data of 2×2 pixels from original image data. A converter generates reduced image data having a size smaller than the original image data by sampling one pixel data at a preset position in the input block data. A generator generates encoded data to restore three non-sampling target pixel data in each block data so as to restore the original image data from the reduced image data generated by the resolution converter. To do this, the generator determines whether all non-sampling target pixels in a block of interest are restorable from a sampling target pixel in the block of interest or from sampling target pixels in three blocks adjacent to the block of interest, and generates and outputs three kinds of additional information based on the determination result.
摘要:
According to this invention, degradation of the image quality of a decoded image is reduced while losslessly encoded data and lossily encoded data coexist. For this purpose, a first encoding unit performs JPEG encoding for each pixel block, and a second encoding unit performs JPEG-LS encoding. Letting Lx be the code length of encoded data generated by the first encoding unit and Ly be the code length of encoded data generated by the second encoding unit, an encoding sequence control unit selects one of the two encoded data and stores the selected data in a first memory in accordance with whether Lx and Ly satisfy a predetermined non-linear boundary function f( ): Ly≧f(Lx). At this time, when the axis of abscissas represents the code length of the encoded data generated by the second encoding unit and the axis of ordinates represents that of the encoded data generated by the first encoding unit, the non-linear boundary function f( ) has a curved portion at the two code lengths.
摘要:
In this invention, image data expressed by one component is encoded at a high speed by using a color image lossless encoder. To do this, a color conversion unit converts color image data read by a document reading unit into C, M, Y, and K data. In a color reading mode, a switching unit directly outputs the C, M, Y, and K data to an encoding unit. If the reading mode is a monochrome reading mode, the switching unit neglects the C, M, and Y components of the C, M, Y, and K data. Every time four K components are input, the switching unit supplies the four K components to the encoding unit as pseudo data of C, M, Y, and K color components. The encoding unit lossless-encodes the received C, M, Y, and K component data.
摘要:
Resolution interpolation data is generated by relatively simple processing. This enables image encoding by simple and quick processing to attain high image quality and high compression performance. To do this, a tile divider extracts tile data of 32×32 pixels from encoding target original image data. A resolution converter samples one pixel of a block of 2×2 pixels in the tile data, thereby generating reduced tile data of a reduced image. An interpolation data generator generates interpolation data to be used to generate tile data having the original resolution from the reduced tile data. Based on the interpolation data of a tile of interest, an encoding method selector outputs a control signal indicating which one of lossless encoding and lossy encoding should be executed for the reduced tile data. A code stream generator outputs the generated encoded data and interpolation data as encoded image data.
摘要:
According to this invention, encoded data of a target data amount is generated by one image input operation while both lossless encoding and lossy encoding are adopted. For this purpose, a first memory stores encoded data of a shorter encode length among encoded data generated by a first encoding unit which performs lossy encoding and encoded data generated by a second encoding unit which performs lossless encoding. A second memory stores encoded data from a second encoding unit. When an encoding sequence control unit determines that the encoded data amount in the first memory has exceeded the target data amount, the encoding sequence control unit discards data in the first memory, sets a quantization parameter for a higher compression ratio for the first encoding unit, and causes the first encoding unit to execute encoding. Encoded data before the encoded data amount is determined to have exceeded the target data amount is re-encoded by a re-encoding unit.
摘要:
According to this invention, encoded data of a target data amount is generated by one image input operation while both lossless encoding and lossy encoding are adopted. For this purpose, an encoding sequence control unit controls a first encoding unit for lossy (JPEG) encoding, a second encoding unit for lossless (JPEG-LS) encoding, first and second memories, and a re-encoding unit, and stores, in a first memory, encoded data of a target data amount or less that contains both losslessly and lossily encoded data. A correction unit corrects, of encoded data stored in the first memory, encoded data of an isolated type to the type of neighboring encoded data, and outputs the corrected data.
摘要:
An object of this invention is to increase the encoding efficiency of attribute data of each pixel of image data by using the fact that the probability that the attribute flag data of adjacent pixels have the same bit position is higher than the probability that the attribute flag data of adjacent pixels have the same value. In the first phase, to encode 32×32 attribute data having a size of 8 bits corresponding to one pixel, input attribute data is directly output to an encoding unit and encoded. In the second phase, “7” is set in a variable i as the initial value. Eight attribute data are input. Eight-bit data including bits i is generated and output to the encoding unit. The data of bits 7 of 32×32 attribute data are encoded. After that, the variable i is changed to “6”, and the same process described above is executed. This process is repeated until the variable i reaches 0. The amounts of encoded data generated in the first and second phases are compared. Data with a smaller amount is selected and output.